Melo, M F Vidal

Abstract Rationale Postoperative pulmonary complications (PPCs) importantly contribute to postoperative morbidity and mortality, particularly for American Society of Anesthesiologists (ASA) physical status III patients. It remains unclear whether risk factors for PPCs depend on sex. We hypothesised that sex modifies the relationship between perioperative risk factors and PPCs in ASA III patients undergoing noncardiothoracic surgery with general anesthesia. Methods We performed a secondary analysis of prospective data from 1,202 ASA III patients undergoing non-cardiothoracic surgery. Data consisted of preoperative demographics, comorbidities, intraoperative physiology, medications, and procedure information. The primary outcome was a composite of PPCs by postoperative day 7. Mixed-effects linear models incorporated sex as main effect and interaction with covariates. Results Age, chronic obstructive pulmonary disease, upper abdominal surgery, surgical duration, and emergency surgery significantly increased the odds of ≥ 1 PPC by postoperative day 7. Male patients presented a higher rate of ≥ 3 PPCs, and mechanical ventilation was less protective in female patients. Yet, sex did not significantly modify the relationship between perioperative factors and the primary outcome (no p<0.05 for the interaction effect with sex). In the secondary analysis, gastroesophageal reflux disease affected atelectasis more strongly in male than female patients (relative odds-ratios for female versus male =0.27; 95% CI 0.13 to 0.57). Conclusions In ASA III patients undergoing non-cardiothoracic surgery with general anesthesia, perioperative factors are predominantly not significantly modified by sex in their relationship to PPCs. GERD’s association with atelectasis in male patients could be explored in future prospective studies as a target for reducing pulmonary complications. This abstract is funded by: NHLBI - UH3 HL140177